GLISTIN-A Data Format
Data format descriptions
Each of the following floating point files are available in both SCH and map (latitude/longitude) coordinates, and all are in little endian format.
- Height (.hgt) - topographic height in WGS-84 datum. Floating point format, 4 bytes per pixel, unit in meters.
- Correlation (.cor) - raw correlation value computed without corrections for SNR and geometric decorrelation. Floating point format, 4 bytes per pixel, little endian, unitless.
- Radar image intensity (.pwr) - arithmetic mean of the two interferometric channels. Floating point format, 4 bytes per pixel.
- Height precision (.prc) - height error estimate computed from raw correlatioin, the number of looks, and the sensitivity of height with respect to phase. Floating point format, 4 bytes per pixel. Ranges from less than 50 cm in the near range to 5 m in the far range at 3 m x 3 m posting.
- Terrain slope (.slp) - derivatives of the height file in along track and cross track direction for data in SCH coordinates, and derivative of the height file in East and North direction for data in map coordinates. The file is an array of two interleaved floating point numbers (2 x 4 bytes per pixel). For each interleaved pixel in SCH coordinates, the first 4 byte value is the terrain slope in the cross track direction, and the second 4 byte value is the slope in the vertical track direction. For each interleaved pixel in map coordinates, the first 4 byte value is the terrain slope in the east direction, and the second 4 byte value is the slope in the north direction. Unitless.
- Local incidence angle (.inc) - angle between the surface normal and the radar line of sight for each pixel, coregistered with the slope file. Floating point, unit in radians.
- Annotation file (.ann) - text file containing meta data describing the data set, including image dimension and format.
File Naming Convention
The file name is in the following format: SiteNm_LinID_FltID_DT#_YYMMDD_ALBsln_PL_VV.ext.crd
Example product name: greenl_09803_16026_007_160320_ALTTBB_HH_01.hgt.grd
Where:
- SiteNm - 6 character site name as an abbreviation for the desired target site (image may contain other sites).
- LinID - 5 character line ID describing a unique track where the 3 digit aircraft heading is followed by a 2 character incremental counter. (this is set during flight planning)
- FltID - 5 digit flight ID describing the unique flight the line is flown in, where the first two digits are the last two digits of the year, and the next three digits are the flight number by UAVSAR counted sequentially from the first flight of the year.
- DT# - 3 digit data take counter indicating which acquisition during the flight this data was from, counted sequentially from the beginning of the flight and starting from zero.
- YYMMDD - 6 digit acquisition date indicating the year, month, and day the data was collected in UTC time.
- AL - A for Ka-band indicating the frequency band of the radar, L for Left looking
- Bsln - 4 character baseline: T stands for top, B stands for bottom
- PL - 2 character polarization, HH for horizontal transmit and horizontal receive.
- VV - 2 digit version number of the product. Data processed with different processing and/or calibration parameters will be released under different version numbers.
- ext - 3 digit extension describing the data product layer
- crd - coordinate system: sch or grd (for map or latitude/longitude system)